Braganhol Elizandra, Bruno Alessandra Nejar, Bavaresco Luci, Barreto-Chaves Maria Luiza M, Sarkis João José Freitas, Battastini Ana Maria Oliveira
Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
Neurochem Res. 2006 Apr;31(4):449-54. doi: 10.1007/s11064-006-9041-y. Epub 2006 May 17.
Neonatal hypothyroidism is associated with multiple and severe brain alterations. We recently demonstrated a significant increase in hydrolysis of AMP to adenosine in brain of hypothyroid rats at different ages. However, the origin of this effect was unclear. Considering the effects of adenine nucleotides to brain functions and the harmful effects of neonatal hypothyroidism to normal development of the central nervous system, in this study we investigated the metabolism of adenine nucleotides in hippocampal, cortical and cerebellar astrocyte cultures from rats submitted to neonatal hypothyroidism. ATP and AMP hydrolysis were enhanced by 52 and 210%, respectively, in cerebellar astrocytes from hypothyroid rats. In hippocampus of hypothyroid rats, the 47% increase in AMP hydrolysis was significantly reverted when the astrocytes were treated with T3. Therefore, the imbalance in the ATP and adenosine levels in astrocytes, during brain development, may contribute to some of the effects described in neonatal hypothyroidism.
新生儿甲状腺功能减退与多种严重的脑部改变有关。我们最近证明，在不同年龄的甲状腺功能减退大鼠的大脑中，AMP水解为腺苷的过程显著增加。然而，这种效应的起源尚不清楚。考虑到腺嘌呤核苷酸对脑功能的影响以及新生儿甲状腺功能减退对中枢神经系统正常发育的有害影响，在本研究中，我们调查了新生期甲状腺功能减退大鼠海马、皮质和小脑星形胶质细胞培养物中腺嘌呤核苷酸的代谢情况。甲状腺功能减退大鼠小脑星形胶质细胞中ATP和AMP水解分别增强了52%和210%。在甲状腺功能减退大鼠的海马中，当星形胶质细胞用T3处理时，AMP水解增加47%的情况显著恢复。因此，在大脑发育过程中，星形胶质细胞中ATP和腺苷水平的失衡可能导致新生儿甲状腺功能减退中所描述的一些效应。
